Comparative Life Cycles and Life Histories of North American Rhabdias Spp. (Nematoda: Rhabdiasidae): Lungworms from Snakes and Anurans

AbstractMost animal species have a complex life cycle (CLC) with metamorphosis. It is thus of interest to examine possible benefits of such life histories. The prevailing view is that CLC represents an adaptation for genetic decoupling of juvenile and adult traits, thereby allowing life stages to respond independently to different selective forces. Here I propose an additional potential advantage of CLCs that is, decreased variance in population growth rate due to habitat separation of life stages. Habitat separation of pre- and post-metamorphic stages means that the stages will experience different regimes of environmental variability. This is in contrast to species with simple life cycles (SLC) whose life stages often occupy one and the same habitat. The correlation in the fluctuations of the vital rates of life stages is therefore likely to be weaker in complex than in simple life cycles. By a theoretical framework using an analytical approach, I have (1) derived the relative advantage, in terms of long-run growth rate, of CLC over SLC phenotypes for a broad spectrum of life histories, and (2) explored which life histories that benefit most by a CLC, that is avoid correlation in vital rates between life stages. The direction and magnitude of gain depended on life history type and fluctuating vital rate. One implication of our study is that species with CLCs should, on average, be more robust to increased environmental variability caused by global warming than species with SLCs.

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Life Histories of North American Geometridae. —IV

Psyche A Journal of Entomology ◽

10.1155/1899/89303 ◽

1899 ◽

Vol 8 (281) ◽

pp. 407-408 ◽

Cited By ~ 1

Author(s):

Harrison G. Dyar

Keyword(s):

North American ◽

Life Histories

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Life Histories of North American Geometridae—XXIII

Psyche A Journal of Entomology ◽

10.1155/1901/70451 ◽

1901 ◽

Vol 9 (303) ◽

pp. 226-227 ◽

Cited By ~ 1

Author(s):

Harrison G. Dyar

Keyword(s):

North American ◽

Life Histories

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Community structure, life histories and secondary production of stoneflies in two small mountain streams with different degree of forest cover

Journal of Limnology ◽

10.4081/jlimnol.2015.1262 ◽

2015 ◽

Author(s):

Pavel Beracko ◽

Andrea Kušnírová ◽

Michaela Partlová ◽

Jana Ciceková

Keyword(s):

Community Structure ◽

Secondary Production ◽

Life Histories ◽

Forest Cover ◽

Adult Emergence ◽

Life Cycles ◽

Mountain Streams ◽

Annual Life Cycle ◽

Forested Stream ◽

The Difference

Our study examines community structure and nymphal biology (life cycles and secondary production) of stoneflies in two adjacent mountain streams with different degree of forest cover in the Prosiečanka River Basin (Chočské Vrchy Mts., West Carpathians). One of the streams has non-forested catchment, converted to meadows and pastures, while the other one has catchment with 60% covered by spruce forest. Differences in forest cover and in thermal regime of the streams were reflected by the difference of stonefly communities at their structural and functional level. Species Nemoura cinerea and Leuctra aurita created stonefly assemblage in non-forested stream, whereas Nemoura cinerea also occurred in naturally forested stream together with species Leuctra armata, Leuctra nigra, Leuctra prima, Siphonoperla neglecta and Arcynopteryx dichroa. All examined species had maximally annual life cycle and in eudominant species Nemoura cinerea one month shift was found in nymphal hatching and adult emergence between streams. Total secondary production of stoneflies in undisturbed stream (126.46 mg DW m-2 y-1) was more than two times higher than the production in non-forested stream (47.39 mg DW m-2 y-1).

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Life Histories of North American Geometridae—VIII

Psyche A Journal of Entomology ◽

10.1155/1900/794523 ◽

1900 ◽

Vol 9 (285) ◽

pp. 9-10 ◽

Cited By ~ 1

Author(s):

Harrison G. Dyar

Keyword(s):

North American ◽

Life Histories

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Life Histories of North American Geometridae.—I

Psyche A Journal of Entomology ◽

10.1155/1899/372690 ◽

1899 ◽

Vol 8 (273) ◽

pp. 310-311 ◽

Cited By ~ 1

Author(s):

Harrison G. Dyar

Keyword(s):

North American ◽

Life Histories

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Life Histories of the Frogs of Okefinokee Swamp, Georgia. North American Salientia (Anura), No. 2. By Albert Hazen WWright. New York: Macmillan Co. 497 pp., 44 pls

Annals and Magazine of Natural History ◽

10.1080/00222933208673552 ◽

1932 ◽

Vol 10 (55) ◽

pp. 135-136

Keyword(s):

New York ◽

North American ◽

Life Histories

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Hybridization in leopard frogs (Rana pipiens complex): terrestrial performance of newly metamorphosed hybrid and parental genotypes in field enclosures

Canadian Journal of Zoology ◽

10.1139/z01-119 ◽

2001 ◽

Vol 79 (9) ◽

pp. 1552-1558 ◽

Cited By ~ 9

Author(s):

Matthew J Parris

Keyword(s):

Growth Rates ◽

Life Histories ◽

Parental Species ◽

Natural Populations ◽

Life Cycles ◽

Natural Hybridization ◽

Evolutionary Potential ◽

Leopard Frogs ◽

Rana Blairi ◽

Advanced Generation

Terrestrial ecology has been largely neglected in the study of amphibian life histories because it is difficult to manipulate most species during the terrestrial stage. I examined the terrestrial performance of Rana blairi, Rana sphenocephala, and four hybrid (two F1 and two advanced generation) genotypes in replicated experimental enclosures to test for differences in traits related to juvenile terrestrial fitness. I produced all genotypes by means of artificial fertilizations using frogs collected from natural populations in central Missouri, and juvenile frogs were obtained from larvae reared in experimental ponds. Following metamorphosis, froglets were raised in single-genotype groups in terrestrial enclosures through the first overwintering. The proportion surviving did not vary among genotypes, but the power to detect significant differences was low. F1 hybrid genotypes BS and SB demonstrated significantly higher growth rates than either parental species or advanced-generation hybrid genotypes. Observation of growth rates of advanced-generation hybrids equal to those of the parental species, and heterosis in F1 hybrids for growth rate, suggests that natural hybridization between R. blairi and R. sphenocephala can produce novel and relatively fit hybrid genotypes. Direct measurement of multiple fitness components for hybrid and parental genotypes is critical for assessing the evolutionary potential of natural hybridization in organisms with complex life cycles.

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